Mononuclearly filled microcapsules

ABSTRACT

Described are mononuclearly filled seamless microcapsules comprising:
         a capsule shell of a hardened capsule material based on an acid polysaccharide and   a filler material surrounded on all sides by the capsule shell, including an organoleptitic effective amount of a flavor,
 
wherein the microcapules is heat stable and/or cooking stable and/or deep fry stable and the water portion in the capsule shell is adjusted to a value of ≦50 wt. %, based upon the total mass of the capsule shell.

CROSS REFERENCE TO RELATED APPLICATION

This application is a national stage of PCT/EP02/014732 filed Dec. 23,2002 and based upon DE 101 64 110.9 filed Dec. 24, 2001, under theInternational Convention.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention concerns mononuclearly filled microcapsules,foodstuff compositions and other articles which include one or moremononuclearly filled microcapsules as well as processes for productionof mononuclearly filled microcapsules.

2. Related Art of the Invention

In the field of encapsulation of active ingredients (active substanceson or in carrier materials) there are frequently problems in particularin the field of foodstuff technology, for example, the incompleteimmobilization of the active substances on or, as the case may be, inthe carrier material.

In the field of the systems for functionalizing, in particular therelease (freeing) of active ingredients (active substances) from out ofthe carrier materials, these types of problems frequently result from aninappropriate, that is, either incomplete or however also possibly earlyor delayed, release of the active substance from out of its carriermaterial.

Although in certain applications, in particular in pharmacology,agrarian chemicals and cosmetics, active substance-carrier materialcombinations have already been found, which meet the requirements bothwith respect to the encapsulation efficiency as well as with respect tothe requirements in practice regarding releasing, nevertheless in allindustrial nations great investment has been made in searching forsystems which in certain areas of application make possible asituation-appropriate release of active substances out of a carriermaterial.

Despite extensive efforts, until now only relatively few functioningsystems have been discovered for encapsulation and functionalizing ofingredients in the area of foodstuff technology and foodstuff chemistry.This is due in part to the limited approval of possible carriermaterials for the respective ingredients. In particular however problemsoccur with those types of flavors or fragrances, of which thecomposition is complex, which is expressed in the diversity of thevolatilities and the range of polarity of the individual aromacomponents of the fragrance or flavor as well as in the sensitivity ofone or more of the fragrance or flavor components to externalinfluences.

From the highly developed field of literature regarding activeingredient—release systems, reference can be made to the followingdocuments:

Brandau, Thorstein; Pharma+Food 3/2001, 8-12:

In this document microencapsulated active substances and microspheresare described in pharmaceutical and cosmetic applications. As processesfor production of microspheres, the so-called microsphere process isspecified, which results in highly spherical granules (solid spheres)with monomodal grain size distribution. The one or more active substanceis evenly distributed throughout the entire sphere, in a matrix of thecarrier material. Further, microcapsules are described, for theproduction of which a liquid or liquefied active substance is embeddedin a solid shell.

WO 93/02785:

This document discloses a process for production of alginate spheres(solid spheres) from droplets of an alginate solution, wherein dropletsare released from a nozzle and allowed to drop into an ion solution,which solidifies them. The alginate solution is rendered into dropletsby oscillation excitation. Mononuclearly filled capsules are notdisclosed.

WO 98/15191:

This document discloses a process for production of spheres (beads) asnutrient—additives, wherein these solid spheres are loaded with at leastone active ingredient selected from the group of flavor substances.Mononuclearly filled capsules are not disclosed. Data or informationregarding ingredients from the field of flavors or fragrances, inparticular water insoluble flavors or fragrances, and technicaladvantages of the carrier material with respect to heat stability aredisclosed, wherein however the release is not spontaneous, but ratheroccurs continuously during manufacture or preparation, in particularhowever during storage of the nutrients.

WO 98/15192:

This document discloses a process for production of spheres (beads) asnutrient—additive, wherein in a finishing process step previouslymanufactured water insoluble spheres (solid balls) are retroactively orsubsequently loaded with at least one active, amphiphilic ingredient.

The encapsulation of taste substances (flavor substances) in spheres(beads) brings about that the flavor substances possess an improvedthermal stability and water insolubility during the further processingof the beads. The flavor release is however not instantaneous duringchewing or breaking of the bead-particles in the mouth, but rather isbased upon a continuous and slow process of diffusion of active flavorcomponents out of the encapsulated material into the foodstuff matrix.This is described in particular in WO 98/15191 and in WO 98/15192.

EP 0 513 603 B1:

This document discloses a process for production of seamless capsules,in which a fluid stream is blown out of multiple nozzles for theformation of capsules, so that droplets are formed, which are thenbrought into contact with a hardening fluid, in order to produce theseamless capsules. These seamless capsules are mononuclearly filled.Information regarding capsule materials is not provided. Informationregarding possible ingredients or possible technical advantages of theshell materials in practical applications are likewise not provided.

JP 11155480 A describes microcapsules filled with oily aromaticingredients, which are obtained by reaction of polysaccharides such asalginates with calcium or metal ions and which are heat and waterresistant. The shells of the described capsules exhibit however a highwater proportion of greater than 90 wt. %, based upon the capsule shell.

JP 09065853 A describes a microcapsule filled with the flavor substancewasabi which is formed with sodium alginate and a polysaccharide as formand stabilizing adjuvant by means of a two-fluid nozzle and is hardenedwith calcium chloride. However here the hardened capsule shell materialpossesses a very high water content, greatly above 50 wt. %.

A high water content in the capsule is very disadvantageous for theperformance of a capsule and in particular for its heat stability andits flavor retention value, as has been determined by variousexperiments within the framework of the present invention.

SUMMARY OF THE INVENTION

It is accordingly a primary task of the present invention to provide aflavor release composition and a process for production thereof, whichis efficient with respect to the primary flavor encapsulation and whichis universally employable as widely as possible with respect to theselection of the flavors to be encapsulated, that is, in particular, notlimited to a certain few oil soluble essences.

Beyond this, the process to be provided should preferably make itpossible to produce an at least substantially water insoluble flavorrelease system, with which the encapsulation of water soluble fillermaterials is also possible.

The system should further include or possess in its flavor releasecomposition preferably instantaneous release characteristics, that is, astriking release of the flavor at the desired point in time, preferablyduring ingestion of the nutrients (burst effect).

At the same time the systems to be provided should be resistant to shearforces, preferably at least in such a degree, that they are notdisturbed by the shear forces occurring during the normal manufacture orpreparation of a foodstuff (nutrient preparation).

Beyond this, the flavor release system to be provided should be heatstable and/or cooking stable and/or deep fry stable (for the definitionof these terms, see below).

In technical respects the process to be provided should make possible acontinuous production of a homogenous-shaped release system.

With respect to the flavor release system, the primary task is solved byprovision of a mononuclearly filled seamless microcapsule, whichcomprises

-   -   a capsule shell of a hardened capsule material based on an acid        polysaccharide and    -   a filler material completely enclosed by the capsule shell,        including or comprising an organoleptically effective amount of        a flavor        wherein the microcapsule is heat stable and/or boiling or        cooking stable and/or frying or deep fry stable and wherein the        water proportion in the capsule is adjusted to a value of ≦50        wt. %, based upon the total mass of the capsule shell.

A mononuclearly filled seamless microcapsule is to be considered heatstable when it maintains its structural integrity when immersed for 15minutes in a water bath at 50° C. Its structural integrity is moreparticularly said to be retained, when the filler material has notleaked from the microcapsule following the handling of the microcapsule.

A mononuclearly filled seamless microcapsule according to the inventionis considered boiling or cooking stable, when it maintains itsstructural integrity when subjected to 5 minutes in a water bath at 100°C. It structural integrity is verified particularly when the fillermaterial does not leak from the capsule following the treatment of themicrocapsule.

A mononuclearly filled seamless microcapsule according to the inventionis to be considered frying or deep fry stable when its structuralintegrity is maintained following subjecting to 5 minutes in a deep frybath of molten palm oil at 180° C. It structural integrity is verifiedparticularly when the filler material does not leak from the capsulefollowing the treatment of the microcapsule.

Among mononuclearly filled (micro) capsules there is to be understood,within the framework of the present disclosure, exclusively systemswhich possess a defined capsule (capsule shell, jacket), whichcompletely enclose a single (mono) core (nucleus) of filler material.Therein the layer of thickness of the capsule shell can be variable,preferably the core assumes the substantially larger proportion of thecapsule volume, in order to make possible a high loading of the capsule.The term or concept “mononuclearly filled microcapsule” is thus inparticular not applicable for “microspheres”, as they have described forexample in the above-mentioned article in Pharma+Food 3/2001. The justmentioned sphere—systems, in which the active ingredient is present inthe form of a finally divided imbedded emulsion or dispersion in thecarrier material, are accordingly usually referred to in the literatureas “polynuclear capsules”. A microcapsule in the sense of the presentdisclosure has a maximal volume of 65 mm³.

An inventive mononuclearly filled seamless microcapsule can be producedin particular by a process with the following steps:

-   -   providing a liquid, organoleptically effective amount of a        flavor-including filler-material for the microcapsules,    -   providing a preferably aqueous solution or dispersion of a        hardenable capsule material based upon an acid polysaccharide,    -   forming discrete droplets of the liquid filler material for the        microcapsules and the solution or dispersion of the hardenable        capsule (shell) material, so that the hardenable capsule        material surrounds on all sides the liquid filler material in        the droplets,    -   hardening the hardenable capsule (shell) material, so that        seamless polysaccharides are formed, which respectively surround        the filler material mononuclearly, and which are heat stable        and/or cooking stable and/or deep fry stable,    -   drying the formed microcapsules, until the water content in the        capsule shell reaches a value of≦50 wt. %, based upon the total        mass of the capsule shell.

Preferably a liquid filler material is produced, in that a solution oremulsion of the active flavor substances to be employed (which togetherproduce the organoleptically effective amount of a flavor) is produced.

It is preferred to produce the discrete droplets of the liquid fillermaterial and the solution or dispersion of the hardenable capsulematerials in that the mentioned liquids are sent through a concentricmulti-nozzle arrangement. The discrete droplets then include at leasttwo different phases (filler material, capsule or encapsulatingmaterial).

The hardening of the hardenable capsule material preferably occurs inthat the hardenable capsule material, which in the formed discretedroplets surrounds on all sides the liquid filler material, is contactedwith an aqueous solution of multi-valent cations (for example Ca-ions),whereupon the acid polysaccharides react with the cations in order toform a seamless solid shell about the liquid filler material.

Following the hardening of the hardenable capsule material the formedcapsules are separated from the employed multi-valent cation containingsolution in conventional manner, and namely preferably following a veryshort contact between capsules and hardening bath.

The drying of the formed capsule shell occurs preferably at leastpartially by a water adsorption or absorption process, which in certaincases can be combined with other drying processes, for example aconvective air drying process.

Prior to drying, the capsules separated from the hardening bath arepreferably also washed in order to remove any residual multi-valentcations from the capsules surface.

Further details regarding the design of the preferred process are setforth below.

The present invention is also concerned with articles or products, inparticular foodstuff compositions, which include one or more inventivemononuclearly filled microcapsules and a carrier material for themicrocapsules (M).

Mononuclearly filled microcapsules which are suitable for humanconsumption are already known. Therein is to be distinguished (a)capsules which are producible by means of multiple nozzle technology,(b) cellular capsules, and (c) coacervation microcapsules.

Regarding capsules type (a) reference is made in particular to the abovecomments regarding documents JP 11155480 and JP 09065853 A.

With respect to the capsule type (b), that is, the cell capsules,reference is made to the documents EP 242 135 A2 and EP 528 466 A1,which respectively disclose encapsulation of active substances in cellmaterial originating from microorganisms.

With respect to capsule type (c), that is, coacervation microcapsules,reference is made to the documents WO 93/19621 and WO 93/19622.

The capsule types (b) and (c) or, as the case may be, the correspondingprocesses for their production, possess certain advantages and certaindisadvantages. Disadvantageous are the conventional manufacturingprocesses for both capsule types still being batch processes, so that aneconomic capsule mass production is not possible. The preparation ofsuitable microorganism cells and the encapsulation in such is besidesthis technically very demanding and highly liable to problems, and theobtained cell capsules are besides this not particularly stable againstshear forces. The processes for production of coacervationmicrocapsules, which are conventionally carried out with gelatin and anadditive such as for example gum arabic, is only suitable under theprecondition that the flavor filling material to be surrounded iscompletely insoluble in an aqueous solution of the gelatin, whichresults in a commensurately large reduction with respect to thepotential complex flavors to be encapsulated. According to the documentsWO 93/19621 and WO 93/19622, the active components to be encapsulatedare limited to oil soluble components. Coacervation microcapsules arebesides this, as a rule, not heat stable, which further substantiallyreduces their employability.

In order to illustrate the enormous investment which is being carriedout in the industry in order to compensate for the above-describeddisadvantages of the above-described capsule systems and to produce heatstable active substance releasing systems with a high as possible numberof potential encapsulable flavors, reference is made to the followingdocuments:

U.S. Pat. No. 5,759,599

This document discloses a process for flavoring and production offoodstuffs by supplementation with flavor oil loaded capsules which arehardened by means of chemical cross-linking and thus more heat stable,which are produced by a coacervation process based upon a protein asshell forming material, and which during chewing are mechanicallyfractured. As discussed above, these capsules can only be loaded withoil soluble flavor substances.

WO 99/17871

This document discloses a process for encapsulation of amphiphilicflavors in chemically cross-linked coacervation microcapsules, which onthe basis of known distribution coefficients are disadvantageouslytransported from outside into the core of a premanufactured non-flavoredcapsule, and there are dissolved until reaching a defined equilibrium.

In contrast to the known types of mononuclearly filled capsules, themicrocapsules according to the present invention are, in the case of theappropriate design of the manufacturing process, shear force stable,water insoluble, flavor and heat stable (capsules are not dissolvable inthe presence of water), without requiring that a supplemental chemicalcross-linking reaction be carried out. The inventive production processis significantly simpler than the production of cell capsules orcoacervation microcapsules and results also in significantly moreuniform microcapsule products. The inventive capsules can be produced bya continuous process and with substantially more constant dimensions. Incomparison with the microcapsules which are described in the documentsJP 11122480 A and JP 09065853 A, the inventive microcapsules arecharacterized in particular by an improved heat stability and animproved flavor retention.

The hardened microcapsule (shell) material of the inventivemicrocapsules comprise—as already described—preferably a substancepreferably hardened by contacting with mono-, di- or higher valuecations. In the inventive process it is thus preferred to employ anappropriate hardenable substance, which for this is preferably in theform of a solution. Preferred are substances which harden on contactwith Ca-ions, for example following dropping into a Ca-ion containingbath.

The capsule (shell) material for the microcapsules is in preferablemanner selected from the group comprising alginate, pectate, pectinate,carrageenan, gellan and their mixtures. The listed materials aresolidifible via cations and form in the hardened state particularly heatstable and water insoluble capsules with a high shear stability.Suitable cations for hardening the listed materials are know to theperson of ordinary skill.

The inventive mononuclearly filled seamless microcapsules include intheir filler materials an organoleptically effective amount of a flavor.This flavor includes preferably one or more flavor substances in thesense of the European Union Flavor Guidelines 88/388/EWG, that is, oneor more fragrance and flavor imparting substances which are presenteither naturally in consumables (for example in fruits) or are added toconsumables in order to impart thereto appropriate fragrance and taste.

It has been found to be particularly advantageous that the inventiveemployed flavor can possess ampliphilic characteristics and need not betransported into the filler material by diffusion from outside followingproduction of the capsule shell.

Within the framework of the present invention it is in general importantto employ measures which ensure that during the production nounacceptable amount of the flavor defuses out of the filler materialinto the capsule shell and in certain cases even out of this. This typeof measure includes for example the (rapid) separating of the capsulesfrom the hardening bath, the washing of the capsules and the drying ofthe capsules (see above). Frequently the inventive mononuclearly filledseamless microcapsules include as filler material a lipophilic solvent(for example a plant oil), in which a flavor is dissolved. In theproduction of the inventive microcapsules there is generally employedbesides this an aqueous solution of a hardenable capsule material. Thedistribution of a (for example amphiphilic) flavor substance between thefiller and the capsule material during the production of the inventivemicrocapsules can be described by the corresponding or appropriatedistribution coefficient. For reasons of providing a better overview ofthe invention it is however more convenient to provide, in place of thedistribution coefficient for the concentration equilibrium between thephase filler material and the capsule material, the distributioncoefficient between n-octanol and water, which in the literature areconventionally employed for characterizing substances. For a giventemperature (for example T=25° C.) the relationship of theconcentrations of a given flavor substance in the two phases n-octanoland water is constant; the distribution coefficient K_(o/w) is amaterial constant, just like the absorption logarithm of thedistribution coefficient logK_(o/w) (also characterized as logP_(o/w)).It is true that logK_(o/w) (=logP_(o/w))=log₁₀[C_(o)/C_(w)] with c_(o)=concentration of a flavor substance in n-octanol; C_(w)=concentrationof the same flavor substance in water.

For the purpose of the present invention the flavor substances can bedivided into three groups, depending upon their logK_(o/w) and namelyso, that each group is associated with a degree of difficulty forencapsulation of the respective flavor substance.

Flavor substances with a logK_(o/w)≧2 are lipophilic compounds, whichare quite easy to encapsulate. An inventive microcapsule can include inthe filler material (core) more than 50 and up to 95 wt. % of flavorsubstances with a logK_(o/w)≧2, based upon the total mass of thecapsule. In this first group of flavor substances there are substancessuch as carvone (logK_(o/w)=2.23), gamma-decalactone (logK_(o/w)=2.42),ethyl-caproate (logK_(o/w)=2.83), linalool (logK_(o/w)=3.28) andbeta-pinene (logK_(o/w)=4.37).

Flavor substances with a logK_(o/w) between 1 and 2 can be considered asampliphilic compounds and are already more difficult to encapsulate. Amicrocapsule according to the invention can include in its fillermaterial (core) at least 10 wt. % and up to 50 wt. % of flavorsubstances with a logK_(o/w) between 1 and 2, based upon the total massof the capsule. In the second group of flavor substances there aresubstances such as ethyl butyrate (logK_(o/w)=1.77), benzaldehyde(logK_(o/w)=1.64), isoamyl alcohol (logK_(o/w)=1.28), ethyl propionate(logK_(o/w)=1.24) and diacetyl (butanedione) (logK_(o/w)=1.33).

Flavor substances with a logK_(o/w)≦1 are ampliphilic to hydrophilicsubstances and are particularly difficult to encapsulate. A microcapsuleaccording to the invention can include in its filler material at least 1wt. % and up to 10 wt. % of flavor substances with a logK_(o/w)≦1, basedupon the total mass of the capsule. In this third group of flavorsubstances there are substances such as ethyl lactate (logK_(o/w)=0.88),anisaldehyde (logK_(o/w)=0.95), butyric acid (logK_(o/w)=0.78),ethylacetate (logK_(o/w)=0.75).

For organoleptic reasons the flavor contained in dissolved or dispersedform in the filler material of the microcapsule according to theinvention usually contains at least 10 wt. %, based upon the total massof the flavor in the filler material, of one or more flavor substanceswith a logK_(o/w)<2. If the flavor is present in the filler material indissolved form, then the proportion of flavor substances with alogK_(o/w)<1 should however be maintained as small as possible in orderto prevent unacceptable flavor losses and preferably not more than 1 wt.%, based upon the total mass of the flavor in the filler material. Ifthe flavor in the filler material is in dispersed form, for example anemulsified form, then the danger of a passage over of flavor substancesinto the capsule shell is reduced in comparison to a dissolved flavor,so that also one or more flavor substances with a logP_(o/w)<1.0 can becontained in the flavor, for example in the range of 0.5-3.0 wt. % basedupon the total mass of the flavor in the filler material.

It becomes possible with the inventive process to produce mononuclearlyfilled microcapsules in which several or all of the followingcharacteristics coexist:

-   1. High retention of amphiphilic active substance components (in    particular flavor substances) in the core during the hardening and    drying of the shell material up until the finished end products;-   2. High stability of encapsulated active substance components during    storage;-   3. Low interaction between filler material and capsule material;-   4. High formal and/or mechanical and/or chemical stability of the    microcapsule relative to conditions as they exist conventionally    during the further processing of microcapsules (for example mixing,    frying, baking or cooking).-   5. Controlled but rapid release of the active substance contained in    the filler material at the intended end-use of the microcapsules,    that is, for example, during eating of a consumable which includes    microcapsules filled with flavor substances.

For production of the filler material (for example, the core of themicrocapsule), there is—as already described—usually first produced (a)a solution of the flavor substance to be incorporated in an oil or (b) awater-in-oil emulsion, which includes in its inner aqueous phase theflavor substance. The term “oil” includes for the purposes of thisinvention both liquid plant oils as well as meltable plant or animalfats. As a rule it is advantageous to select an oil which readilydissolves the flavor substance to be taken up and at the same time issuitable for human consumption. In the case of employment ofwater-in-oil emulsions it can be advantageous to include emulsifiers inthe oil phase, which are suitable to stabilize the emulsion. By additionof a small amount of water, which preferably does not exceed 10 wt. %(based upon the liquid filler material) and a suitable emulsifier with aHLB-value (hydrophilic-lipophilic balance) of preferably less <5 withinthe filler material (core system) it becomes possible to produce astable water-in-oil emulsion. The emulsifiers are, for this purpose,preferably selected from the group consisting of mono-diglycerides,monoglycerides, polyglycerol esters, sorbitan esters and their mixtures.The production of the water-in-oil (w/o) emulsion within the fillermaterial (core phase) improves the retention of the water soluble flavorsubstance. The emulsifier can also be included in the oil phase in thesolution without addition of water. The emulsifier includes the morewater soluble flavor substance components within the liquid fillermaterial in the form of micelles.

Flavor substances which are solid at room temperature can be dispersedin liquid oil, wherein in certain cases dispersion aids can be added.

For producing the solution or dispersion of a hardenable capsulematerial based upon an acid polysaccharide, in accordance with theinventive process conventionally the polysaccharide material, forexample the sodium salt of the alginic acid, is dissolved or dispersedin an aqueous solvent. Non-volatile, water soluble or water insolubledispersible substances can be added at this time, for example (a)glycerin, propyleneglycol or other agents for improving the mechanicalcharacteristics of the (dried) mononuclearly filled microcapsules to beproduced by plastifying of the capsule (shell) or (b) proteins and/orsaccharides for modification of the capsule composition.

In a preferred inventive process the solutions or dispersions of thehardenable capsule material and the liquid filler material are addedseparately from each other into a system, for example a multi-nozzlesystem, wherein the system is so designed, that discrete droplets areformed from the fluid filler material for the microcapsules and thesolution or dispersion of the hardenable capsule material for themicrocapsules, wherein the hardenable capsule material encloses orsurrounds the liquid filler material. Suitable double nozzle systems aredescribed in the literature, and for this reference is again made to thedocuments EP 0 513 603 B1 and WO 93/02785.

The said discrete droplets are comprised of an inner flavor core (fillermaterial), which is enclosed on all sides by the outer polysaccharideshell (capsule jacket). Core, shell and whole capsule are preferablyspherical. The core phase is preferably centered exactly within thecapsule shell phase, which means, that the thickness of the capsuleshell at each point of the seamless microcapsule is the same. A designof this type contributes in great amount to a qualitatively high valuedcapsule. The centering of the capsule core (filler material) can beachieved by a suitable selection from the following parameters:relationship of the diameter of inner and outer nozzles; relationship ofthe flow-through rates through the inner and the outer nozzle; frequencyand amplitude of the optionally present vibrator for the multiplenozzles; intrinsic characteristics of the employed liquids (for fillermaterial and capsule (shell) material).

For hardening of the formed discrete droplets these are introduced ordropped into a preferably aqueous or water-alcohol solution ofmulti-valent cations. The selection of the multi-valent cations isadapted to or based on the type of the employed hardenable capsulematerial. To the extent that calcium ions can be employed for hardeningof an employed acidic polysaccharite, the solution of multi-valentcations preferably includes a dissolved calcium salt, wherein dissolvedcalcium chloride with a concentration in the range of between 1 and 10wt. % (based upon the total mass of the liquid hardening bath) ispreferred. The solution of multi-valent cations is generally produced inthat the corresponding salts are dissolved in deionized water or in tapwater, to which a low molecular weight alcohol such as ethanol orisopropanal can be added, (a) in order to reduce the surface tension ofthe solution and therewith to facilitate the emersion of the discretedroplets produced at the nozzle, (b) adjusting the concentration theaqueous solution of the multi-valent cation containing salt (for examplecalcium salt), and/or (c) to influence the gelling of the capsulematerial (for example alginate).

Alternatively to introducing or dripping the discrete droplets into asolution of multi-valent cations, the fine droplets can also be sprayedwith a solution of multi-valent cations.

As capsule materials, particularly suitable are alginate, that is linearco-polymers of -L-guluronate (G) and-D-mannuronate (M). The alginatechain can be envisioned as a block co-polymer, comprised of “G-blocks”(homopolymer regions of guluronic acid residues), “M-blocks”(homopolymer regions of mannuronic acid residues) and “MG-blocks”(copolymer regions of mixed alternating sequences of M and G) ofvariable length. Alginates exhibit, besides a variable chemicalcomposition, also a broad molecular weight distribution, so that theconcept alginate is a generic term encompassing an entire family ofpolymers. The characteristics of each respective alginate depend on itsblock structure and its molecular weight.

Above a critical molecular weight the characteristics of an alginate areessentially determined by its monomer composition and block structure.Generally, an increase of the content of guluronate leads to an increasein mechanically stable gels with elevated stability in the presence ofnon-, or as the case may be, anti-gelling ions such as sodium andmagnesium as well as calcium complexing compounds; alginate gels with ahigh guluronate proportion possess in general an elevated porosity andtend during their gel formation only slightly towards syneresis. Incomparison thereto, alginate gels become softer and more elastic byincreasing the mannuronate proportion, and the corresponding gels shrinkmore strongly during their gel formation, which results in a reductionin porosity.

For the encapsulation of active substances (in particular flavorsubstances) in principle all alginate types are suitable; those with amannuronate proportion above 40% are however preferred for theproduction of the microcapsules according to the invention for use infoodstuff applications, since they are comparatively elastic and exhibitsmall porosity, which has beneficial effects in flavor applicationssince they are comparatively elastic and exhibit low porosity, which isbeneficial for flavor use in applications in which heat and therewithflavor retention during the further processing have an impact. On theother hand, in the case that an intentional continued release of aflavor substance out of the inventive capsules under the influence ofheat, steam or air, is desired, that is, conditions as are presentfrequently in the case of tobacco products, guluronate rich alginateswith large pores are preferred. Due to their comparatively rapid gellinghigh molecular alginates are preferred for the encapsulation of flavorsubstances. For modulating the viscosity of an alginate gel it canhowever be of advantage to substitute high molecular alginates partiallywith low molecular alginates; the viscosity of an alginate gel isresponsible, besides other factors, for the size or magnitude of themicrocapsules formed in accordance with the inventive process and forthe capsule thickness (shell thickness). The viscosity of the alginategel has, besides this, a direct influence on the elasticity of theformed capsule.

For hardening (gelling) of alginate calcium ions are preferred, and thisin particular due to their high effectiveness, the low cost associatedwith their employment, and their non-toxicity. Other divalent metal ionssuch as those of zinc, copper, etc. can likewise be employed, likewisethe ions of the di- or trivalent ions, aluminum, etc. As counter ions ofcalcium the salty and slightly bitter tasting chloride is preferred forcost reasons; acetate and/or lactate are however preferred for tastereasons. During the contacting of discrete droplets, which includealginate as the hardenable capsule material, with calcium ions, a skinof insoluble alginate gel immediately forms. Subsequently thereto,calcium ions slowly diffuse into the capsule shell. For droplets with adiameter of 100 to 5000 micrometers and an aqueous solution of 1 to 10wt. % calcium chloride the optimal contact time is less than 1 minute,it could however in certain cases be longer and for example can be 100minutes. If the flavor includes water soluble components, it is howeverof advantage to remove the formed capsules already after a short timeout of the calcium bath, in order to prevent the transmission ofwater-soluble compounds into the bath, or at least to maintain thiswithin acceptable limits. It is to be noted that the loss of watersoluble flavor components out of an alginate capsule occurssignificantly more slowly than the loss of corresponding aromacomponents out of a comparable microsphere; these losses withmicrospheres are described in the document WO 98/15191. The abovecomments with regard to calcium ions and alginate apply in appropriatemanner to other pairings of an acid polysaccharide and mono- ormulti-valent cations.

Although the attention has been focused primarily in particular on thevarious types of alginate and thereunder again in particular sodiumalginate, for the production of the capsules according to the inventionalso other low esterified pectins or other acid polysaccharides can beemployed, in particular to produce water insoluble, heat stable gelcapsules.

The concentration of the acid polysaccharide (hydrocolloid) in theliquid mixture, from which the capsule (shell) is to be produced, liespreferably in the range of between 0.5 and 4 wt. %, based upon the totalmass of the solution. Concentrated solutions are as a rule difficult toprocess, since they have a high viscosity. The polysaccharide solutionscan have additives such as locust bean gum, saccharose, glycerine orpropylene glycol, in order to improve the mechanical characteristics ofthe capsule (shell) material. Fillers such as for exampleoligosaccharides, maltrodextrin, starches, gum arabic or cellulosederivatives (for example carboxymethyl cellulose) can be dissolved inthe polysaccharide solution or be dispersed therein, in order to improvethe barrier characteristics of the capsules, in that they fill thepores, which would otherwise be present in the open structure of thelater formed gel.

The hardened capsules, or capsules in the process of hardening, can beseparated from the suspension (capsules in ion containing solution) forexample by filtration or centrifugation. The result is moist mononuclearfilled microcapsules, to which can be added for example an anti-cakingagent, in order to maintain a free flowing (pourable) product. The stillmoist product can be dried under atmospheric pressure or reducedpressure, in order to produce a capsule product with defined watercontent. In the same manner it becomes possible to adjust or tweak themechanical stability of the microcapsules.

The inventive capsules have a volume of up to 65 mm³; howeverparticularly in the field of flavoring technology significantly smallervolumes are preferred. Preferred volumes lie in the range of between4×10⁻⁶ m³ and 2×10⁻⁹ m³; these correspond in the case of preciselyspherical shaped microcapsules to a diameter of between approximately200 and approximately 1500 μm. Preferably, the volumes of themononuclearly filled microcapsules according to the present inventionlie in the range of between approximately 3×10⁻⁷ m³ and 3×10⁻⁵ m³; thiscorresponds in the case of spherical shaped microcapsules to a diameterin the range of approximately 400 to approximately 1200 μm.

The filler material for the inventive mononuclearly filled microcapsulescontain flavor substances. The concept “flavoring substance” includesnatural flavor substances, flavor substances identical to natural,artificial flavor substances, flavor extracts, reaction flavors andsmoke flavors, according to European Union-Flavor-Guidelines 88/388/EWG.

A large number of flavors and flavor ingredients can be encapsulatedwith the process according to the present invention. The flavors includecompounds such as menthol, natural extracts, essences, complex mixturesof extracts, essential (etheric) oils, oleo resins (a mixture of anessential oil and a resin) or reconstituted natural, true to natural orartificial flavors. The group of natural extracts, essences and oleoresins includes fruit essences, vanilla extract, paprika oleo resin,pepper oleo resin, cinnamon oil, oil of wintergreen, peppermint oil, bayor laurel oil, thyme oil, curled mint oil, cassia oil, citrus oil andthe like. The group of reconstituted natural, natural-like andartificial flavors include apple, cherry, strawberry, peach as well assausage, cheese, tomato, celery and butter flavor. These flavors can beemployed individually or as mixtures, according to known processes.Depending upon their respective logK_(o/w) value the flavors and flavoringredients can be incorporated in varying upper limit amounts in theinventive capsules (see the above remarks regarding degree of difficultyof encapsulation depending upon logK_(o/w)). As particularlyadvantageous, it is to be pointed out or emphasized that also slightlyvolatile and amphiphilic or as the case may be water soluble flavorsubstances, as are key components for the reconstruction of fresh,fruity and plant notes, can be incorporated in sufficiently high amountin the inventive capsules and can be maintained therein even during thefurther processing of the capsules.

Filled microcapsules in accordance with the present invention, of whichthe filler material includes one or more flavor substances, are adaptedfor instant release of the flavor substance by mechanical opening(fracturing) of the polysaccharide capsule. The capsule does notinterfere with eating. The person of ordinary skill would design thethickness and stability (rupture resistance) of the polysaccharidecapsule (shell) depending upon the requirements of the intendedemployment; he would for this in particular select a suitable hardenablecapsule material and employ plasticizers as necessary. In this manner itbecomes possible to produce for example inventive filled microcapsulesof which the filler material includes one or more flavor substances, andit can be incorporated for example in a foodstuff or consumable. Duringchewing of the foodstuff there would thus occur a spontaneous release ofthe flavor substance wherein, in contrast to the processes for flavoringof consumables known from the state of the art, none or onlyinsignificantly small amounts of flavor substance are retained by thematerial of the microcapsule.

The inventive microcapsules are formulated to be heat stable and/orboiling or cooking stable and/or frying or deep frying stable. Theseterms have the meanings described above and make it clear that themicrocapsules in accordance with the invention, in comparison to systemsknow in accordance with the state of the art, have a particularly goodflavor retention in semi-solid or sold foodstuff products duringcooking, baking, boiling, deep frying, frying, drying, extruding,microwave heating, etc. The microcapsules according to the inventionprotect the flavor substances contained therein in hot liquid productsvery well against decomposition and escape, and namely in particularduring pasteurizing and/or sterilizing of products into which they areincorporated.

The person of ordinary skill in this art is capable of modifying oradapting the composition of many flavors in particular with respect tocomponents of amphiphilic or hydrophilic nature to the capsule system,such that acceptable sensoric results can be achieved. In order to guardagainst loss of active substances of the amphiphilic or hydrophiliccomponents characteristic for the respective flavor during hardening anddrying of the capsules, the inventive process when using theconventional nozzle system, as described for example in EP 0 513 603 B1,or WO 93/02785 and the therein cited documents, is preferably sodesigned, that (a) the hardenable capsule material first comes intocontact at the tip of the nozzle with the active substance contained inthe filler material selected from the group of flavor substances and (b)during or as the case may be following the hardening of the hardenablecapsule material the one or more aroma substances are not, or as littleas possible, defused into the capsule surrounding the filler material.The person of ordinary skill is capable based on tests to determinesuitable process parameters on the basis of the known or predictabledistribution coefficients, which prevent or at least reduce thetransition of flavor substances into the capsule material and beyondthis into the hardening bath or the atmosphere.

It is possible for the person or ordinary skill to have in mind, atleast essentially, the composition of the flavor contained in the fillermaterial and the organoleptic profile thereof. Components such as forexample isoamyl acetate (logP_(o/w)=2.12), ethyl butyrate(logP_(o/w)=1.73) and benzaldehyde (logP_(o/w)=1.64), which areamphiphilic in nature and of which the water solubility significantlyincreases in this sequence, represent the respective characteristics oras the case may be typical components for banana, pineapple and cherryflavor. Production conditions targeted to conserve these flavors make itpossible for the person of ordinary skill, within the framework of thepresent invention, to achieve an almost complete retention orpreservation of these flavor substances in the dried microcapsules inaccordance with the invention.

The retention of flavor substances such as isoamyl alcohol, of which thelogP_(o/w) of 1.22 means a renewed elevation of the water solubility incomparison to the three above-mentioned substances, is maintained atleast within acceptable boundaries using process conditions targetedthereto in accordance with the invention, while non-adaptedmanufacturing conditions would practically lead to quantitative losses.

Acetealdehyde, which is responsible for the fresh characteristic ofvarious fruit flavors, has a logP_(o/w) of −0.16 compared to isoamylalcohol and thereby exhibits yet again a significantly increased watersolubility. Quantitative losses of this flavor substance can occurduring hardening and drying if it was contained in dissolved form in thefiller material.

Even retention of highly water soluble substances such as acetaldehydecan however be significantly increased by appropriate measures, in orderalso to retain within the core of the capsule the sensoric activity, forexample by dispersion of solid flavor substances or simply water in oilemulsions, micellular systems or liposomes in a case of liquid flavors.

For applications which require heat processing of the final foodstuff,there are preferred in accordance with the invention free-flowing(pourable) microcapsules, dry on their outer side, with a waterproportion of ≦50 wt. % in the capsule shell based upon the mass of thecapsule shell, in comparison to capsules with a water proportion in thecapsule shell of ≧50 Wt. %. In the case that the water proportion is ≧50wt. %, flavor substances can escape from the microcapsule in the heatalong with the then surplus or excess free water steaming out of themicrocapsule. Dry capsules, for example calcium hardened capsules with awater content of ≦50 wt. % in the capsule shell, based upon the totalmass of the capsule shell, can be hydrated only with difficulty, so thateven a heat exposure in the presence of water does not immediatelyresult in disruption of the active substance releasing system; thiswould be different in certain cases were the inventive capsules to havea higher water proportion of, for example ≧50 wt. % in the capsuleshell, and also in microspheres known according to the state of the art,which include flavors embedded in a matrix, which when heated in thepresence of water are less stable than the preferred inventivemicrocapsules, which have a water proportion of ≦50 wt. % in the capsuleshell; in the case of capsules with a filler material proportion of 80wt. % and a capsule shell proportion of 20 wt. %, respectively, basedupon the total mass of the capsule, the water proportion corresponds toless than 10 wt. % based upon the total mass of the capsule.

According to a preferred process design two-phase discrete droplets aredripped into a hardening bath, wherein the impacting of the droplets iscushioned or reduced to the extent possible, in order followinghardening of the capsule (shell) material to produce a centered core (offiller material). The person of ordinary skill in the art would, inorder to accomplish this, reduce the distance between the multi-nozzlesystem and the hardening bath and/or would in a first step spray thediscrete droplets with the hardening solution while they are stillfalling, before the droplets submerge in the hardening bath and/or wouldmodify the amplitude and frequency of a conventional vibrator associatedwith the multi-nozzle system and/or would adapt the intrinsiccharacteristics of the capsule shell and liquid core phase and/or woulduse certain overflow funnel systems or channel systems and/or wouldemploy tension reducing compounds in the hardening bath, which wouldproduce a foam upon the surface of the hardening bath or would reducethe surface tension of the hardening bath.

The polysaccharide solution forms a solid skin about the core material(filler material) immediately upon contact with the multi-valentcations. Thereafter the cations slowly diffuse out of the hardening bath(the hardening spray) into the internal of the capsule shell, so that ahardening gradient forms, wherein at the outer side of the capsule shella comparatively high hardness and on the inner side of the capsule shella comparatively low hardness exists (see also below). The person ofordinary skill would determine on the basis of tests at which point intime in the hardening process the gelled microcapsules are to be removedfrom the hardening bath.

If amphiphilic flavor substances are employed, it is to be expected thatthe hydrophilic compounds within a flavor substance mixture would bethose which would be first to diffuse out of the core phase (fillermaterial phase) into the aqueous polysaccharide solution, while thediscrete droplets following exiting the multi-nozzle jet are justforming, and in a second step diffuse through the capsule shell which isin the stage or process of hardening and diffuse in the directiontowards the hardening bath. The droplet forming and the hardening stepsare thus preferably carried out in the shortest possible time inaccordance with the invention. It is known that polysaccharide solutionsbased upon alginate, gellan or pectin, in contact with multi-valentcations such as for example calcium, form an inhomogeneous structure.The cations attach initially only to the outer surface of the outerpolysaccharide phase of the mentioned discrete droplets and diffusesubsequently towards the center wherein they develop a so-called gelgradient. The capsule shell strength is thus greater on the outersurface of the already formed microcapsule than inside, and in the innerpart of the gel phase this is liquid or of soft consistency. Themolecular chains of the hardening hydrocolloid are contracting, whereinsimultaneously a certain amount of water is pressed or extruded out ofthe gel. This phenomenon is known as the syneresis effect, and theshorter the gel time, the smaller the syneresis effect. Depending uponfactors such as gel time, the polysaccharide solution concentration, andthe cation solution concentration, the syneresis can make a differenceof between 5 wt. % and 60 wt. %, based upon the mass of the originalliquid droplet. A certain amount of hydrophilic flavor substance canescape in this manner (by syneresis) and along with the accompanyingwater be transported into the hardening bath. According to a preferredembodiment of the present invention the gellation time, that is, thecontact time between the formed polysaccharide phase of the capsule andthe bath with multi-valent cations, is reduced to a minimal value, whichpreferably is less than 1 minute and in particular in the range ofbetween 5 and 30 seconds. The inhomogeneity of the formed gel and thereduced syneresis effect attenuate the migration of the saturatedhydrophilic flavor substance out of the core phase (filler material)through said gel phase into the hardening bath. This is an importantpoint of distinction in comparison to the above described microcapsuleswhich are produced by coascervation and of which the contact timebetween the forming microcapsules and the aqueous reaction bath is inthe realm of hours or even days.

The isolation or removal of the formed microcapsules out of thehardening bath is preferably carried out continuously, and namelypreferably by means of a sieve technique or by centrifugation. At thetime point of separation from the hardening bath the microcapsules arein a wet state. The water content of the moist microcapsules liesbetween 50 and 90 wt. %, based upon the total mass of the particle. Thewater exists both as water bound to the polysaccharide as well as freewater within the porous structure of the polysaccharide gel, and asinterstitial water between the formed microcapsules. The water stillcontains a not insignificant concentration of multi-valent cations.According to a preferred embodiment, following separation of the moist(wet) microcapsules from the solution of multi-valent cations (hardeningbath) a washing step is carried out. For this, a washing solution isemployed, which is preferably comprised of deionized water, however maybe a mixture of water and an organic solvent such as for example ethanolor isopropanol. The washing step is preferably integrated into theseparating step, wherein a spray nozzle for application of a washingsolution is incorporated in the separating device employed forseparating. In this manner the multi-valent ions, which are stillpresent in the interstitial water of the microcapsules and in the outerpart of the polysaccharide gel, can be rapidly washed out. This preventsa further diffusion of the reactive multi-valent cations into thepolysaccharide gel and prevents thus also a further syneresis effect.Microcapsules which are subjected to a process with a short gelling timecan still loose up to 50 wt. % on the basis of the syneresis effect, inthe case that the microcapsules are left standing unwashed followingseparation from the hardening bath.

Due to the tendency of the hydrophilic flavor substances to exit out ofthe inner phase (core; filler material) of the moist microcapsulesthrough the porous polysaccharide gel structure of the capsules (shell)material, in accordance with a preferred embodiment of the presentinvention the still moist microcapsules are converted as rapidly aspossible into the dry form. The drying process leads thereto, that theporous shell structure of the microcapsules further contracts until apoint at which even the hydrophilic flavor substances can hardly diffusethrough the dried capsule shell matrix. The drying can either be carriedout in a batch or continuously, wherein however a continuous processdesign is preferred, in order to shorten the time span between the abovedescribed washing of the moist microcapsules and the drying step. Eachstanding time of the moist microcapsules can lead to a further syneresisand therewith to a further transport of hydrophilic flavor substancesout of the microcapsules.

In the framework of the present invention the conventional dryingprocesses can be employed, for example with use of conductive dryers(such as standard ovens or vacuum ovens) or convective dryers (forexample whirlwind dryers with rotating dryer). These techniques arehowever suited when primarily or even almost exclusively lipophilic andnon-volatile flavor substances are contained in the filler material(core). When, in comparison, water soluble or slightly volatile flavorsubstances are to be encapsulated, then an important part of thesematerials can vaporize with a simply water evaporation, an effect, whichis critical in particular in the case of convective drying processes, inwhich a particularly high proportion of flavor substances can be removedfrom the filler material, since vaporizable substances are continuouslytransported away via the air stream. In a preferred design of thepresent invention the said drying techniques are employed in a predryingstep, in which the water content of the capsule shell material remainshigh and therewith the sympathetic (i.e., along with the water)evaporation of hydrophilic flavor substances remains tolerable oracceptable. Wet microcapsules frequently have a water content, whichlies between 96 wt. % and 65 wt. %, based upon the total mass of thecapsule shell material. With the pre-drying preferably less than 25% ofthe total water to be removed is evaporated. In such a manner flavorsubstances with a logK_(o/w)<2, in particular logK_(o/w)<1.5 areparticularly effectively encapsuled.

According to a further alternative embodiment of the present invention adrying technique is employed, in which the preferably washed moistmicrocapsules or the saturated dried microcapsules are contacted with awater adsorbing or water bonding substance. As water absorbing or waterbonding substance, preferably an organic salt such as for examplemagnesium carbonate, magnesium sulfate, calcium chloride, is employed,or compounds such as silicon dioxide, zeolite or starch. Preferred inmany cases is a silicon dioxide, which preferably has an internalspecific surface area of 150 m²/g or more. The water up-take capacity ofsuch a silicon dioxide (also referred to as silica) should be greaterthan 100% and preferably above 200%, based upon its own mass. First thestill moist or predried microcapsules are conventionally homogenouslymixed with up to 50 wt. % and preferably approximately 25 wt. % of thesaid silica. For mixing, a drum mixer, spiral mixer, paddle mixer orplow share mixer can be employed. Following a mixing time, which shouldnot exceed 10 minutes and is preferably approximately 5 minutes, themicrocapsules are separated from the loaded water adsorbing or bondingsubstance using a sieve technique. For this, vibrating or rotatingsieves can be employed. The mixing and sieving can either be carried outin a batch or as a continuous process. The capsule shell material of thedried microcapsules has a water content of maximally 50 wt. %, basedupon the mass of the capsule shell. The advantage of such a dryingprocess in comparison to the above mentioned standard drying techniquesis in particular in (a) a shorter process time, (b) the absence of aflavor substance emission in the air, (c) the good flow ability of thedried microcapsules even with high flavor loading and, in particular,(d) in the improvement with respect to the water soluble and volatileflavor substance component or proportion. Flavor substance with alogK_(w/o)<2 and in particular logK_(w/o)<1.5 are significantly betterencapsulated than when using the conventional drying techniques. Theimprovement with respect to the retention can be as much as 50 to 90 wt.% based upon the starting mass of the employed flavor components in thefilling material, see Example 10.

The inventive microcapsules have a water proportion in the capsule shellof ≦50 wt. %, based upon the total mass of the capsule shell. Asubstantial reason therefore is that internal research has shown thatmicrocapsules with a higher water proportion in the capsule shell losean unacceptable high proportion of their highly volatile and their watersoluble flavor substances when they are heated within their foodstuffmatrix. The more water soluble and volatile compounds are entrained inthe evaporating water and transported out of the microcapsules, so thatthis can be referred to as co-distillation. The thermal stability of theinventive microcapsules with a water content of ≦50 wt. % in thecapsules shell is based not alone on its physical integrity, on thebasis of its water insolubility, and its irreversible gel formation. Itis based also and not least thereupon, that the flavor profile of theoriginal encapsulated flavor system is conserved in unchanged formalcomposition. An inventive microcapsules with a filler material, whichhas a proportion of at least 80 wt. %, based upon the total mass of thedried capsule, and of which the capsule shell material is accordingly aproportion of at most 20 wt. %, should generally have a water content ofnot more than 10 wt. %, again based upon the total mass of the driedmicrocapsules. In the case of a filler material proportion of 90 wt. %the water content should not be above 5 wt. %.

The invention is described in greater detail in the following on thebasis of examples.

EXAMPLE 1

Process for producing inventive (standardized) capsules for use inExamples 2 through 50.

Sodium alginate (type Protonal LF20/60), FMC BioPolymer, Drammen,Norway) was dissolved in demineralized (deionized) water with stirring(15.0 g alginate for 1000 ml water), until a clear solution is produced.The stirring time at a water temperature of 8-15° C. was approximately30 minutes. The solution was allowed to rest at least 3 to 5 hours priorto processing in order to obtain the desired viscosity of maximally 200mPa·s, better yet since the previous day; solutions which are older than24 hours are no longer usable. After the stirring process the pH of thesolution was measured and in certain cases set to pH 6.5-7.5 with base.Tank A was filled with this solution.

A selected flavor concentration or an essence was mixed with neutral oil(for example Miglyol, CONDEA Chemie GmbH, Witten, Germany) or acommercially available plaint oil (for example soy bean oil) forproducing a solution or dispersion with a defined degree of dilution;this dilute flavor solution was supplied to Tank B and continuouslystirred to avoid demixing. Both solutions were separately pumped viapressure lines to a conventional double nozzle system which wasvibrating, wherein the flavor solution was supplied to the internalnozzle with a diameter of 200 micrometer, the alginate solution wassupplied to the outer nozzle with a diameter of 1000 micrometer. Theflow rate relationship of the two solutions was controlled using twoseparate pressure lines in such a manner that the relationship of theliquid A:B of 10:1 was achieved.

Standard parameters:

-   Internal nozzle 0.3 bar/flow-through 14.0=330 g flavor per hour-   Outer nozzle 0.5 bar/flow-through 20.0=3300 g alginate per hour-   Frequency=160 Hz, amplitude=4.8

Therewith, a two-phase liquid droplet with an average particle diameterof approximately 2.2 mm was obtained with a weight relationship of shellto core of 10:1. By gelling with 10% calcium chloride solution thesedroplets were gelled during 5 minutes (solution of 10 g anhydrouscalcium chloride in 100 g demineralized water).

Due to syneresis during the gelling of the alginate, one obtained amoist capsule with a diameter of approximately 1.6 mm, with flavor corediameter remaining unchanged. The particles are isolated by filtrationand briefly washed with tap water for removal of surplus calcium ions.The filtered and washed particles are dried in a fluidized bed with anair temperature of 50° C. and an air amount of 10 m³/min, wherein theaverage particle diameter of the particles dried by means of thisstandard drying method was reduced to 1050 micrometer. For supportingthe fluidizing of the wet and, at this time, also sticky capsules, 1%magnesium carbonate was added as flow aid material. The average particlediameter, which could most easily be measured by light microscopy andfor which a statically significant member of capsules was determined,exhibited a model distribution, the capsule diameter was determined tobe 1050±100 micrometer. Alternatively a laser bending method (Malvern)was employed for particle size and particle distribution measurement.

The resulting dry standard capsules exhibited on average a core portionof a 80 wt. % and a shell portion of 20 wt. %, wherein the shell had anaverage residual water content of 50%, as determined using a dryingprocess with a halogen dryer.

The dilution of the flavor concentrate with oil in the core of thecapsule was so selected, that in comparative tests with use of aflavoring by means of (a) the corresponding liquid flavor concentrate or(b) a spray dried form, in use the same mass proportion of flavor wasrespectively employed. Therein care was taken that in the flavorizingwith capsules, respectively, a dosing was adjusted or set at between 0.2and 2.0 wt. % capsules, depending upon the end use and the desiredrelease rate, in order to obtain a uniform image. The (comparative)flavorization by means of liquid flavor concentrate occurred accordingthereto on a basis of the employed dilution of the corresponding flavorconcentrate in capsules and the supplemental dilution by encapsulationof the shell portion of partial dried alginate gel. In the employment ofvarying capsule sizes the changed dilution and dosing were givenappropriate consideration.

This type of capsule product was employed in the following examples.

EXAMPLE 2

Chewing gum was produced in accordance with the following formulation.

Formulation Type: Chewing Gum, Sugarfree

TABLE 1 Chewing Mass Raw Material/ Additive Ingredient Wt.-% 01 ChewingGum Base 27.62 02 Xylitol 9.87 03 Sorbitol 48.59 04 Mannitol 11.54 05Glycerin 2.16 06 Aspartam 0.11 07 Acesulfam K 0.11 100.0 Wt.-% (basedupon the total mass of the chewing Flavoring: mass) 08a Capsules -Peppermint Oil 1.0* 08b Capsules - Peppermint Oil 2.0** 08c PeppermintOil 0.64 *corresponds to a peppermint oil portion of 0.64% at anadjusted average capsule size of 1050 micrometer and a flavor dilutionwith oil of 80:20. **corresponds to a peppermint oil portion of 0.64% atan adjusted average capsule size of 800 micrometer and a flavor dilutionwith oil of 80:20.

Production Method

-   a—mixing of 1, 2, 3, 4, 5, 6, 7.-   b—kneading the mass at a temperature of 50° C. until mixture is    homogeneous.-   c—addition of flavor (0.64% ingredient 08c or as the case may be    1.0% ingredient 08a or as case may be 2.0% ingredient 08b) based    upon chewing gum mass (total mass of ingredients 1 through 7).-   d—laminating the mass-   e—cutting into strips

The chewing gum strips were evaluated for fragrance (aroma by sniffing)and taste (chewing gum in the mouth). The result of the organoleptictests (6 test persons) represented in Table 2 showed that theencapsulated aroma with both capsule sizes exhibited significantlyhigher intensity in comparison to the liquid aroma with the same massproportion.

TABLE 2 Intensity of Particle the Aroma Size (mm) Olfactory OralAlginate capsule 1.050 5.25 7.00 (additive 08a) Alginate capsule 0.8006.38 8.40 (additive 08b) Non-Encapsulated 4.50 4.70 (additive 08c)Organoleptic evaluation (flavor strength/intensity): 0 = notdiscernable, 1 = almost imperceptible, 2 = very weak, flavor type hardlyrecognizable; 3 = weak, flavor type just barely recognizable; 4 = weak,flavor type clearly recognizable; 5 = acceptable, somewhat too weak; 6 =acceptable, optimal flavor strength; 7 = acceptable, light to strong; 8= flavor much too strong; 9 = flavor extremely strong, irritating.

EXAMPLE 3 Baking

Biscuits (cracker) were produced in accordance with following formula.

Formula Type: Snack Biscuit, Cheese, Salted

TABLE 3 Additive Raw Material/Ingredient Wt.-% 01 Wheat Flour (Crackertype) 66.530 02 Vegetable Shortening 7.980 03 Raw Sugar 1.550 04Inverted Sugar Syrup 1.550 05 Salt 1.150 06 Ammonium Bicarbonate 0.89007 Malt Syrup Extract 0.806 08 Sodim Monophosphate 0.665 09 SodiumBicarbonate 0.550 10 Citric Acid 0.066 11 Bacterial Protease 0.027 12Sodium Metabisulfite 0.016 13 Water 19.370 100.0 Wt.-% (based upon thetotal Flavorization: mass ot the additives 1-13) 14a Capsules - Cheeseflavor 1.0* 14b Capsules - Cheese Flavor 2.0** 14c Cheese Flavor, topnote, liquid 0.08 *corresponds to a cheese top note proportion of 0.08%with an adjusted average capsule size of 1100 micrometer and a flavordilution with oil in the core of 10:90 **corresponds to a cheese topnote proportion of 0.08% with an adjusted average capsule size of 900micrometer and a flavor dilution with oil in the core of 10:90

Production Method

-   a—mixing 2, 3, 4, 5 and 13 (70° C.), until all components are    dissolved.-   b—addition of ingredients 1 and 6-12 to the dough, addition of    flavor 14a or as the case may be 14b or as the case may be 14c.-   c—mixing for approximately 10 minutes, until the dough is flat-   d—storing the dough for 2 hours-   e—laminating the dough and cutting to size-   f—addition of granulated salt on the cracker dough (optional)-   g—baking for 4 minutes in an oven at 185° C. (at the beginning the    temperature should be 210° C.). Injection of steam while the    crackers are introduced into the oven, this injection being carried    out so long until the temperature reaches 190° C.-   h—during removal of the crackers vegetable fat is sprayed on the    crackers (optional), until the crackers have achieved a certain    shininess.

The crackers were evaluated for fragrance (aroma by sniffing) and taste(cracker in the mouth). The results of the organoleptic testing (7 testpersons), presented in Table 4, showed that that the encapsulated aromaof both capsule sizes exhibited a significantly higher intensity incomparison to the liquid aroma with the same mass proportion.

TABLE 4 Intensity of Particle the Aroma Size (mm) Olfactory OralAlginate capsule 1.100 5.40 7.00 (additive 14a) Alginate capsule 0.9005.80 8.40 (additive 14b) Non-Encapsulated 4.50 3.88 (additive 14c)Organoleptic evaluation (flavor strength/intensity): 0 = notdiscernable, 1 = almost imperceptible, 2 = very weak, flavor type hardlyrecognizable; 3 = weak, flavor type just barely recognizable; 4 = weak,flavor type clearly recognizable; 5 = acceptable, somewhat too weak; 6 =acceptable, optimal flavor strength; 7 = acceptable, light to strong; 8= flavor much too strong; 9 = flavor extremely strong, irritating.

EXAMPLE 4 Deep Frying

A panade (for bread crumb encrusted product) was produced in accordancewith the following formula:

Recipe Type: Wet Panade

TABLE 5 Additive Ingredients Wt.-% 01 Chicken breast in pieces, 76.0approximately 15 g 02 Salt 1.00 03 Wet panade, BAB 137* 5.80 04 Water10.2 05 Dried panade, Panko 102* 7.00 100.0 Wt.-% (based upon theFlavorizing: total mass of additives 1-5) 06a Flavor, carrot, liquid0.16 06b Flavor, carrot, capsules 1.0** **corresponds to a carrot flavorproportion of 0.16% at a capsule size of 1050 micrometer and a flavordilution with oil in the core of 20:80. *Griffith Laboratories, B-2200Herentals

Production Method

-   a—wet panade (03) and salt (02) dispersed in water, allowed to swell-   b—flavor (06a or 06b) is dispersed in the swollen wet panade    described in a)-   c—meat is added to the flavorized wet panade-   d—allowing to drip, and rolling in dry panade (05)-   e—deep frying the panaded meat pieces in vegetable fat,    approximately 180° C., approximately 4 minutes.

The deep fried chicken breast pieces were sampled for fragrance (aromaby smelling) and taste.

TABLE 6 Application: Chicken Nuggets Flavor: Carrot Aroma- Taste ProfileDosing # Type Profile 1 Profile 2 Profile 3 In Wt.-% 06a Liquid WeakSlightly Weakly 0.16 Flavor Carrot Cabbage Green 06b Capsule TypicalSweet Cabbagy 1.0 Carrot

EXAMPLE 5 Steaming, Deep Frying

The noodles were produced in accordance with the following formula.

Formula Type: Instant, Asiatic

TABLE 7 Additive Ingredient Gram 01 Wheat flour 1000 02 Water 250 03Salt 13 04 MSG 1.2 05 Kansui*** 1.2 06 Guar Gum 0.4 1265 .8 Wt.-% (basedupon the Flavorizing: total mass of ingredients 1-6) 07a Leek aroma,capsules  1.0%* 07b Leek aroma, spheres   1.0%** 07c Leek aroma,spraydried Product (20 parts flavor, 80 Parts Maltodextrin/ GumArabicum) 0.25% *correspondes to a leek flavor portion of 0.05% -corresponding to 0.25% of the corresponding spraydried product - with anadjusted capsule size of 1050 micrometer and a flavor dilution by oil inthe core of 5:95%. **corresponds to a leek flavor portion of 0.05% -corresponding to 0.25% of the corresponding spraydried product - at anadjusted sphere size of 500 micrometer and an embedded flavor content of5%. **alkali solution (imparts to the noodles a fresh, light tinglingsour taste) comprised of: 05a calcium carbonate 0.96 05b sodiumcarbonate 0.12 05c sodium polyphosphate 0.12

Production Method

-   a—mixing and pressing: ingredients 01-07 are blended in a dough    kneader. The result is a crumbly mass, which is pressed together on    a plate with a noodle wood (roller).-   b—5 minutes allowing to rest-   c—rolling out the dough: a dough plate was extruded ever thinner    using a domestic noodle machine between two rollers, maximal 1.1 mm.-   d—cutting the noodles (the extruded dough plate was pressed between    two rippled rollers on a perforated sheet in fine noodle rods.-   e—steaming (the whole sheet with the noodles were cooked in a    steamer for 3 minutes at approximately 4 bar at 100-110° C. not    fully cooked (instant characteristic of the noodles)-   f—deep frying-   g—the noodles were deep fried for 50 seconds in hot palm oil at    155-160° C. Subsequently the surplus oil was allowed to drip off,    the noodles were cooled and packed—by deep frying the noodles became    more crunchy, more flavorful and more durable and storage stable.

The noodles were evaluated for fragrance (aroma by sniffing) and taste(in the mouth). The results of the organoleptic testing (7 test persons)are presented in Table 8, and show that the encapsulated flavor, incomparison to the spray-dried flavor at the same dose, always had asignificant preceptibility and recognizability, while the spray-driedflavor and the flavor encapsulated in spheres practically was no longerrecognizable.

TABLE 8 Non-Encapsulated Capsules Spheres* Spraydried Product AfterOnion, Weaker than Slightly-like Pressing green, capsules leek,extremely clearly-like weak leeks Following Green, leek, Too weakLightly oniony, Cutting weaker than weak dough sample Following Lightleek, Too weak Too weak steaming green weak however recognizableFinished Slightly Too weak Too weak Noodles like leek *Matrix embeddedaroma (spheres) were here tested in comparison to capsules, in order torepresent the differences between capsules (co-extruded) and spheres(flavor emulsified, extruded).

EXAMPLE 6 Drying with Silicon Dioxide

15 g sodium alginate (type Protanal LF20/60, FMC Biopolymer) weredissolved in 985 g demineralized water using a high speed kneading mixerof the type Ultra-Turrax until the aqueous solution became clear. Thealginate solution was prepared several hours prior to its use, in orderto enable a complete hydration of the alginate chains. 2 g leek flavorconcentrate were dissolved in 98 g neutral oil (type Miglyol, CONDEAChemie GmbH). The two solutions were separately supplied by means ofgear wheel pumps out of two supply tanks to a vibrating two-streamnozzle head. The nozzle head system included an inner nozzle with 150 μmdiameter and an outer nozzle with 1000 μm diameter. The flow rate of thetwo solutions was so adjusted that it formed a laminator flow out of thenozzle, 400 g per hour flavor solution (leek) through the inner nozzleand 2800 g per hour alginate solution through the outer nozzle. Thevibration thereof was so adjusted that it interrupted the stream andformed homogeneous discrete droplets. At a frequency of 130 Hz two-phasedroplets of approximately 2 mm diameter were formed. The droplets fellinto a 10% calcium chloride reaction bath, so that immediately a solidlayer formed around the liquid filler material. The calcium bath reactorwas comprised of a pipe system, through which the calcium chloridesolution flowed and so continuously transported the fresh gelledcapsules to a separator. The flow rate of the pump for the calciumchloride solution was adjusted to a gelling time of approximately 1minute. The gelled capsules were transported through a pipe reactor andthen separated on an 800 μm sieve. The sieved capsules were washed withtap water. The wet capsules had, due to syneresis which occurred duringthe gelling step, a diameter of only approximately 1.6 mm, with a watercontent of the shell material of 98%. 520 g of wet capsules wet capsuleswere obtained and these were mixed for 10 minutes with 260 g silicondioxide (Sipernat S50, Degussa) and then separated from the silicondioxide on a vibrating 800 μm round sieve. 120 g dried capsules with aparticle size of 1.2 mm were produced. The water content of the shellmaterial of the dried capsules was 49%. The dried microcapsulesincluded, at a total 83 wt. % liquid filler material, a water content of8.4 wt. %.

EXAMPLE 7 Predrying plus Drying with Silicon Dioxide

15 g sodium alginate (type Protanal FL 20/60, FMC Biopolymer) weredissolved in 975 g demineralized water using a high speed kneading mixerof the type Ultra-Turrax. 50 g strawberry flavor and 1 g polyglycerolester (type PGRP 90, Danisco Cultor) were dissolved in 39 g neutral oil,10 g tap water were added, then slowly mixed for approximately 5 minutesand subsequently homogenized for 1 minute with a high speed kneadingmixer of the type Ultra-Turrax in order to produce a stable water-in-oilemulsion. The two solutions were supplied to a vibrating two-streamnozzle head with an inner diameter of 150 μm and an outer diameter of1000 μm. The flow rates were adjusted for the flavor solution to 300 gper hour and for the shell solution to 3000 g per hour, the vibrationfrequency to 180 Hz. Two-phase droplets of approximately 1.8 mm diameterwere formed. The droplets fell in a 10% calcium chloride reaction bath.The flow rate of the pump for the calcium chloride reaction bath wasadjusted to a gelling time of approximately 1 minute. The gelledcapsules were separated on a 800 μm sieve and washed. The wet capsuleshad a diameter of 1.7 mm and a water content of the shell material of97%. 605 g wet capsules were obtained and pre-dried for purposes ofpre-drying in a fluidized bed dryer (type STREA 1, aromatic) with an airflow of 100 m³ per hour and an inlet temperature of 50° C. forapproximately 10 minutes. 490 g pre-dried capsules were obtained, mixedwith 200 g silicon dioxide (Sipernate S50, Degussa) for approximately 5minutes and then separated on a vibrating 800 μm round sieve. 140 gdried capsules with a particle size of 1.1 mm were produced. The watercontent of the shell material was 49%. The total microcapsule included79.1% liquid filler material, the water content was 10.2%.

EXAMPLE 8 Drying with Silicon Dioxide

15 g sodium alginate (type Protanal LF 20/60, FMC Biopolymer) and 10 ggellan gum (type Kelcogel, Kalco) were dissolved in 975 g demineralizedwater using a high speed kneading mixer of the type Ultra-Turrax. 500 gof a peppermint flavor solution was prepared. The two solutions weresupplied to a vibrating two-stream nozzle head with an internal diameterof 200 μm and an outer diameter of 500 μm. The flow rates were adjustedto 500 g per hour flavor solution and 800 g per hour shell solution, thevibration frequency was adjusted to 200 Hz. Two-phase droplets ofapproximately of 1.4 μm diameter were formed. The droplets fell into apipe reactor with 5% calcium chloride solution. The flow rate of thepump for the calcium chloride reaction bath was adjusted to a gel timeof approximately 10 seconds. The gelled capsules were separated on an800 μm sieve and washed. The wet gel capsules had a diameter of 1.2 mmand a water content of the shell material of 96.5%. The objected 1100 gwet capsules were mixed with 275 g silicon dioxide (Sipernat S50,Degussa) for approximately 10 minutes and then were separated for thesilicon dioxide on a vibrating 800 μm round sieve. An amount of 540 gdried capsules with a particle size of 0.9 mm were produced. The watercontent of the shell material was 4.6%. The total microcapsule comprised93.1% liquid filler material, the water content was 3.2%.

EXAMPLE 9 Continuous Gelling Process; Short Gel Time

This example served to demonstrate the improvement which can be achievedwith reference to the flavor component encapsulation in alginatemicrocapsules when the gelling process is carried out as a continuous 1minute process, in comparison to the encapsulation techniques carriedout as a batch process, in which the gelled capsules remain in contactwith the gel bath for hours.

50 g sodium alginate were dissolved in 195 g demineralized water using ahigh speed kneading mixer of the type Ultra-Turrax. 250 g Model-flavorwere dissolved in 750 g neutral oil. The Model flavor was comprised offlavor components, which cover a large spectrum of water/oil solubilityas indicated by logK,/w -values, see the following Table 9.

TABLE 9 Component Amount % (w/w) Log K_(o/w) Anisyl alcohol 5 0.95Ethylpropionate 5 1.24 Benzaldehyde 5 1.64 Isoamylacetate 5 2.12Ethylcaprylate 5 3.9

The two solutions (alginate, flavor) were conveyed to a vibratingtwo-stream nozzle head with an inner diameter of 150 μm and an outerdiameter of 500 μm. The flow rates were adjusted for the flavor solutionto 500 g per hour and for the shell solution to 1000 g per hour, thevibration frequency was adjusted to 200 Hz.

For the preferred short continuous gelling process the formed discretedroplets fell into a pipe reactor, which was filled with 5% calciumchloride, and were so transported, that the dwell time was 1 minute. Theresulting wet capsules were sieved and washed with tap water.

The results of the 1 minute capsule production (corresponding to 8.3 gencapsulated flavor solution) were then dissolved in 200 ml 1% aqueoussodium chloride solution. The mixture was then extracted for 4 hours ina perforator with diethyl ether. The diethyl ether extract was analyzedusing HRGC/MS. The results were evaluated based on the surface of theGC/MS peaks for the components per gram of encapsulated aroma solution.

For the batch gelled process the formed discrete droplets fell into a 5%calcium chloride containing reactor with a dwell time of 2 hours. Theformed wet capsules were thereafter sieved and washed with tap water.The same analytical protocol was carried out as for the short gel timeprocess.

10 g Model-flavor solution were dispersed in 200 ml 1% aqueous sodiumcitrate solution. The mixture was extracted in a perforator for 4 hourswith diethyl ether and evaluated as described above.

The flavor retention for the respective flavor components during theshort continuous gelling process and the long gel batch process werecalculated on the basis of the amount of the Model-flavor solution whichoriginally flowed through the nozzle system and theoretically wasencapsulated, the results are presented in Table 10.

TABLE 10 Flavor Retention: Short Gel Time Long Gel Time Components(continuous) (Batch) Anisyl alcohol 60%  6% Ethylpropionate 61%  0%Benzaldehyde 82% 11% Isoamylacetate 80% 18.5%   Ethylcaprylate 90% 90%

In the process with short gel time the flavor retention of thesubstances with a logK_(o/w)<3.9 was significantly better than in theprocess with longer gel time.

Example 10 Comparison of Various Drying Processes

This example served to demonstrate the differences with regard to flavorretention which exist between conventional convective drying processing(fluidized bed dryer) and the drying process using water adsorbingsubstances.

A sample of the wet capsule product, produced according to the processwith short gel time as described in Example 4, was divided followingwashing into two equal batches of 200 g.

The first batch was dried by addition of 100 g silicon dioxide to thewet capsules. The substances were mixed for 10 minutes and the thendried capsules were subsequently manually separated from silicon dioxideon an 800 μm-sieve. 60 g dried capsules were obtained. The water contentof the shell material of the dried capsules was 45% (corresponding to 7%water content and 84.2% liquid filler material based upon the mass ofthe total capsules).

The second 200 g batch was dried in a fluidized bed dryer (type STREA 1,Aeromatic) at 30° C. in the temperature and 100 m³ per hour air flow, inorder to obtain an amount of dried capsules of 60 g. The water contentof the shell material of the dried capsules was 62% (corresponding to14.4% water content and 76.8% liquid filler material based upon the massof the total capsule).

The varying amounts of liquid filler material, which were found in thetwo dried capsule types, show already the difference with regard to theflavor retention, which are associated with the two drying processes.The silicon dioxide dried capsules had 50.52 g (84.2%) liquid fillermaterial, those capsules dried in the fluidized bed had in comparisononly 46.08 g (76.8%) liquid filler material.

The details of the retention of each flavor component is shown in thefollowing Table 11. The used analytical method was identical with thatdescribed in Example 9.

TABLE 11 Drying “water adsorbing” Substances: Convective Drying: %Retention % Retention Anisyl alcohol 33%  5% Ethylpropionate 50%  4%Benzaldehyde 80% 52% Isoamylacetate 95% 60% Ethylcaprylate  0% 65%

EXAMPLE 11 Influence of the Water Content in the Shell on Heat Stability

This example underscores the importance of the water content presentwithin the shell material of the dried capsule in order to achieve anefficient heat stability of the encapsulated flavor during a heatingprocess.

Capsules with cheese flavor were added to a cracker dough and thenbaked. The capsules had various water content (various degrees ofdrying). The flavor dosing was maintained constant for all tests.

The crackers were prepared according to the following formula (Table12):

TABLE 12 Additive Amount (%) 1 Vegetable Fat 7.98 2 Industrial Sugar1.55 3 Fructose Syrup 1.55 4 Salt 1.15 5 Wheat Flour 66.53 (crackertype) 6 Ammonium bicarbonate 0.89 7 Malt extract syrup 0.806 8 SodiumMonophosphate 0.665 9 Sodium Bicarbonate 0.55 10 Citric Acid 0.066 11Bacterial Protease 0.027 12 Sodium Metabisulfite 0.016 13 Water 19.37Cracker preparation process 1. Mixing the ingredients 1, 2, 3, 4 and 13(70° C.) until they are completely dissolved. 2. Adding 5–12 and thedesired amount of capsules into the dough. 3. Mixing for approximately10 minutes. 4. Allowing the dough to stand for 2 hours at roomtemperature. 5. Rolling out the dough (2 mm) and cutting into crackershapes. 6. Baking in an over at 185° C. (preheating the oven to 210° C.)for 4 minutes.

The crackers were evaluated by a sensory test group (10 persons) withregard to the oral flavor intensity. The evaluation scale ranged from1-5:

-   -   0 no taste    -   1 very weak flavor note, almost not recognizable    -   2 flavor note is too weak    -   3 acceptable taste note    -   4 good and strong taste note    -   5 too strong taste note

The results are summarized in Table 13.

TABLE 13 Mass Relationship Mass Mass Capsule Water/Capsule RelationshipRelationship Sensory Type Shell Capsule/Cracker Flavor/CrackerEvaluation Wet   95% 3.5% 0.04% 1 Lightly   91% 2.7% 0.04% 1 DriedMedium 66.7% 1.3% 0.04% 2 Dried Dried 38.9%   1% 0.04% 4

The dried capsules clearly impart on the basis of their heat stabilitythe best sensory results.

EXAMPLE 12 Effect of Varying Aroma Application Designs

This example shows the varying sensory evaluations of leek flavor, whichwas applied to crackers in liquid form, in stray dried form and inencapsulated form.

The crackers were prepared as described in Example 6 and baked, howeverat 200° C. for 4 minutes. The sensory evaluation of the 3 varying flavorembodiments summarized in Table 14 are based upon the same definition ofscale as in Example 11.

TABLE 14 Mass Relationship (Flavor and Carrier) for Mass Flavor ExampleRelationship Sensory Type Capsule/Cracker Flavor/Cracker EvaluationLiquid 3.5% 0.04% 1 Spray Dried 2.7% 0.04% 2 Capsule 1.3% 0.04% 4

The leek flavor encapsulated in alginate capsules showed the bestresults in regard to the baking stability, compared with the standardflavor embodiments in liquid or, as the case may be, spray dried form.

1. A process for producing mononuclearly filled seamless microcapsules,comprising: a capsule shell of a hardened capsule material based on anacid polysaccharide and a filler material surrounded on all sides by thecapsule shell, including an organoleptitic effective amount of a flavor,wherein the mononuclearly filled microcapules are heat stable and/orcook stable and/or deep fry stable and wherein the water portion in thecapsule shell is adjusted to a value of ≦50 wt. %, based upon the totalmass of the capsule shell, the process comprising the following steps:(a) preparing a liquid organoleptically effective flavor-includingfiller material for the microcapsules, (b) preparing a solution ordispersion of a hardenable capsule material based on acidpolysaccharide, (c) forming discrete droplets of the liquid fillermaterial for the microcapsules and the solution or dispersion of thehardenable capsule shell material, so that the hardenable capsulematerial surrounds on all sides the liquid filler material in thedroplets, (d) hardening the hardenable capsule shell material, so thatseamless polysaccharide capsules are formed, which respectively includemononuclearly filled material and are heat stable and/or cooking stableand/or deep fry stable, (e) drying the formed capsule shells, until thewater content in the capsule shell reaches a value of ≦50 wt. %, basedupon the total mass of the capsule shell, wherein the forming step isperformed using a double nozzle system.
 2. A process as in claim 1,wherein said a solution or dispersion of a hardenable capsule materialis an aqueous solution or dispersion.
 3. A process according to claim 1,wherein in step (e) the seamless polysaccharide capsules are contactedwith a water adsorbing or water binding substance for drying the formedcapsules.
 4. A process according to claim 1, wherein the hardenablecapsule shell material is hardenable by contact with multi-valentcations, and wherein the discrete droplets are contacted with a solutionfor hardening the hardenable capsule material which contains themulti-valent cations.
 5. A process according to claim 4, wherein theformed seamless polysaccharide capsules are washed prior to the step ofdrying the formed capsule shells, in order to remove multi-valentcations from the capsule surface.
 6. A process according to claim 1,wherein the discrete droplets are contacted for maximally 1 minute witha solution for hardening the hardenable capsule shell material, whichsolution contains the multi-valent cations.
 7. A process according toclaim 6, wherein the formed seamless polysaccharide capsules are washedprior to the step of drying the formed capsule shells, in order toremove multi-valent cations from the capsule surface.
 8. A processaccording to claim 1, wherein the liquid organoleptically effectiveflavor-including filler material prepared in step (a) includes at least10 wt. %, based upon the total mass of the flavor in the fillermaterial, of one or more flavor substances with a logK_(o/w)<2.
 9. Aprocess according to claim 1, wherein the liquid organolepticallyeffective flavor-including filler material prepared in step (a) includesat least 10 wt. %, based upon the total mass of the flavor in the fillermaterial, of one or more flavor substances for which the followingapplies: 1<logK_(o/w)<2.
 10. A process according to claim 1, wherein theliquid organoleptically effective flavor-including filler materialprepared in step (a) includes at least 10 wt. %, based upon the totalmass of the flavor in the filler material, of one or more flavorsubstances for which the following applies: logK_(o/w)<1.